Technical Field
The present invention relates to an isolated Clostridium cadaveris ITRI04005 and the uses of the same, especially the uses of Clostridium cadaveris ITRI04005 in the production of an organic compound via fermentation and in genetic modification including (1) providing a genetically modified strain being able to express an exogenous gene or having an endogenous gene with an enhanced expression level, wherein each of the exogenous gene and the endogenous gene is a gene of an enzyme involved in an alcohol production pathway; (2) providing a genetically modified strain that has an endogenous gene with an attenuated expression level or without any expression level, wherein the endogenous gene is a gene of an enzyme participating in synthesis of acetic acid; (3) and providing a genetically modified strain being able to express an exogenous gene or having an endogenous gene with an enhanced expression level, wherein each of the exogenous gene and the endogenous gene is a gene of a heat shock protein (HSP).
Descriptions of the Related Art
In the past, most researches related to Clostridium sp. were about the investigation of the pathogenic strains. Recently, along with the development of biofuels, people paid more attention to the strains of Clostridium sp. that are suitable for the production of biofuel. One example of the stains is Clostridium thermocellum that has superactive cellulose hydrolase(s) and can directly use cellulose to produce ethanol and hydrogen. Relevant description can be noted from such as “Appl Environ Microbiol. 1988 January; 54(1):204-211” by Freier et al., which is entirely incorporated herein by reference. Another example of the strains is Clostridium ljungdahlii that is able to use a combination of a carbon oxide (e.g., carbon monoxide, carbon dioxide) and hydrogen as feedstock for producing ethanol.
Although there are various strains useful in the production of biofuels or chemicals, they typically use the saccharide(s) and peptone contained in a fermentation medium as the carbon source and nitrogen source required for the production of organic compounds, and few of them can use different types of substances as the substrate for fermentation. Metabolic products produced from the substrate metabolism of a microorganism through fermentation are normally a mixture with complicated constituents, and thus one or more purification processes are required for obtaining the desired metabolite(s). For example, butanol, ethanol, and acetone as well as minor organic acids (e.g., acetic acid, butyric acid) could be produced by the acetone-butanol-ethanol (ABE) fermentation process of Clostridium sp. In addition, the tolerance of microorganism to metabolic products is also an important factor influencing the yield of the fermentation. Accordingly, there is still a need in the industry for a microorganism capable of using different types of substrates and providing an excellent yield of target product at the same time, and thus person in the field have been endeavoring the research and development of strains being able to use various feedstock in the production of chemicals or biofuels and having a high tolerance to the products.
The present invention is directed to the above needs. The inventors of the present invention adaptively selected and obtained a novel strain of Clostridium cadaveris, Clostridium cadaveris ITRI04005 which is capable of using saccharide(s) and/or amino acid(s) as the substrate to produce an organic compound. Compared with known Clostridium strains, Clostridium cadaveris ITRI04005 is more suitable for use in a genetic modification to provide a genetically modified strain which is capable of using saccharide(s) and/or amino acid(s) as the substrate to produce an organic acid or an alcohol, has a high specificity of product, and/or has a high tolerance to product. The genetically modified strain can use various feedstock sources to produce chemicals or biofuels, and provides the target product in a good yield.